A thought in passing:
While spellcasting has gotten easier with each edition in D&D, and spells have gotten more ubiquitous to the point that practically everybody in 5E is a spellcaster, it must be admitted that the magic system is one of D&D's big draws and it makes some sense to leverage it.
The magic system has received a lot of criticism, and often perplexes new players, but, even so, I'll agree that it makes sense to leverage it. Just look at 5e: one list of spells serves 13 classes and over 30 sub-classes, letting them share many of the exact same abilities, and thus saving a lot of design work.
You can still have too much of a good thing of course, and 5E may have crossed that line. Maybe 5E makes spellcasting too cheap, easy, and ubiquitous.
Depends on the campaign. It's barely enough magic for a Harry Potter campaign or one inspired by the Myth Adventures dimension of Perv, for instance. Tolkien or 'low fantasy,' or pulp S&S, sure, it's too much. In terms of game balance, better squeeze in all 6-8 encounters between long rests. Wherever you peg magic level in the game, the DM's going to have to adapt it to his campaign, or adapt his campaign to it. It'd take
really robust balance to avoid that.
Some things aren't properly appreciated when you don't pay a price--I could certainly stand to see AD&D rules on spell disruption brought back into play.
You could re-introduce a lot of things like that without rendering casters non-viable. It might lessen their appeal for more casual players, but you just wouldn't do it if you had such players interested in playing casters - heck, you'd probably try to further simplify casting.
Neither of those things are true.
Technically you didn't need an implement (I thought someone might bring that up), but without the enhancement bonus you weren't going to do well out of the higher levels if you did. You needed the free hand, though, you couldn't cast tied-up, for instance. No Still Spell meta-magic or anything.
I guess I mean, "Whichever spell of a given level is optimal, will be spammed repeatedly."
That's a danger of the neo-Vancian system most 5e casters use, yes.
In the case of my party's wizard, he has a tendency to counterspell or dispel any serious magical effect -- which makes the game kind of boring. It means the first few rounds of a mage duel are spent just burning off each other's spell slots with counterspell to no real effect. Then the warriors wade in and finish the poor NPCs off.
I see your point, but that actually sounds kinda genre-faithful, to me. Maybe in a movie it'd be a little more dramatic - the offensive spell would get to manifest in a menacing way before being countered.
Just imagine it like the wizard duel in one of the Conan flicks. Two wizards staring at each other with really intense expressions, groaning, until eventually one of them slumps in defeat and his side falls back.
One example. That one also reminded me of old-school psionic combat.